SMTP filter context objects can be queried for values or have their values set with calls to SMTPFilterQueryContextData and SMTPFilterSetContextData respectively. The values are contained within a variant type called FilterContextDataVariant. Possible value types to set/get are:

FlagDescriptionTypeAccess
SMTP_DATA_SESSION_OBJThe sessionOpaque pointerRead
SMTP_DATA_USER_OBJThe user associated with this contextUDBHandleRead
SMTP_DATA_ENVELOPE_OBJThe envelope associated with the sessionOpaque pointerRead
SMTP_DATA_MESSAGE_OBJThe messageOpaque pointerRead
SMTP_DATA_SESSION_INTERCEPTEDIs the session interceptedboolRead
SMTP_DATA_SESSION_SECUREIs the session secureboolRead
SMTP_DATA_SESSION_CLIENTIPClient IPV4 addressUnicode stringRead
SMTP_DATA_SESSION_LOCALIPLocal IPV4 addressUnicode stringRead
SMTP_DATA_SESSION_MTAIDName presented with HELO/EHLOUnicode stringRead
SMTP_DATA_SESSION_TRUSTEDIs the client trustedboolRead/Write
SMTP_DATA_SESSION_STATECurrent transaction stateintRead/Write
SMTP_DATA_COMMANDRequest methodUnicode stringRead
SMTP_DATA_COMMANDLINEWhole protocol command lineUnicode stringRead
SMTP_DATA_RETURNPATHReturn pathUnicode stringRead
SMTP_DATA_RECIPIENTRecipientUnicode stringRead
SMTP_DATA_MESSAGE_IDMessage idUnicode stringRead
SMTP_DATA_MESSAGE_FILENAMEMessage filenameUnicode stringRead
SMTP_DATA_RESPONSE_STATUSStatus code of the responseintRead/Write
SMTP_DATA_RESPONSE_STATUSTEXTStatus textUnicode stringRead/Write
SMTP_DATA_ROUTING_TAGA tag storeable with response statusUnicode stringRead/Write

 

If you are getting/setting SMTP_DATA_SESSION_STATE then the possible values for the state are: 

StateDescription
SMTP_STATE_INITClient has just connected. No command has been sent yet
SMTP_STATE_HELOClient just sent HELO or we've just processed a message
SMTP_STATE_EHLOClient just sent EHLO or we've just reset AUTH
SMTP_STATE_AUTHClient just sent AUTH. We are now in AUTH processing loop
SMTP_STATE_PostAUTHAuth completed successfully
SMTP_STATE_MAILJust accepted MAIL command
SMTP_STATE_RCPTJust accepted RCPT command
SMTP_STATE_DATAJust accepted DATA command
SMTP_STATE_DATACompleteMessage complete
SMTP_STATE_EXITJust accepted QUIT command